Years of Life Lost (YLL) in the context of DALYs represents what?

• A. Years lived with disability
• B. Years lost due to premature mortality.
• C. Total life expectancy
• D. Quality-adjusted life years

Answer: (B)

YLL measures years of life lost due to death that happens before a standard life expectancy. In the DALY framework, the total burden combines years lost to premature mortality (YLL) with years lived with disability (YLD). To calculate YLL for an individual, subtract the age at death from the standard life expectancy; for example, if the standard life expectancy is 80 and someone dies at 50, that death contributes 30 YLL. This focuses specifically on mortality, not disability. The other concepts are different: years lived with disability is YLD, total life expectancy is the expected lifespan, and quality-adjusted life years (QALYs) are a separate metric that weights years by quality of life.